Most sizeable business organizations have extensive computer systems for managing large amounts of electronic data. These computer systems typically include a central communication service that is shared by multiple individual data processing devices located in one or more data centers or computing laboratories or which are distributed on a less concentrated bases throughout the business organization. Typically, the data center is either centralized within a building which houses the business organization, or multiple data centers are distributed at different physical locations within the building. Examples of central communication services include, internet protocol (IP) networks, telephony networks, financial services networks, product design services networks, product qualification and test services networks, and marketing services networks, among others. The central communication service is also typically used to link to other communication services outside of the business organization. Examples of data processing devices which may be located in the data center include conventional individual and high-capacity computers or computing devices, computer servers, and data storage servers, among others. These devices may be accessed and controlled by individuals working in the data center itself or over the central communication services by other individuals and computer facilities within the organization. Connection and access to the central communication service by each of the data processing devices in the data center is generally controlled by one or a very few central gatekeeper devices, each of which may be a large port count IP access switch. High capacity data communication cables connect each central gatekeeper with the central communication service to accommodate a high volume of data that may pass through each central gatekeeper. Each data center typically has its own central gatekeeper. The central gatekeeper in each data center also communicates data between the numerous data processing devices within each data center, as well as communicating data to the central communication service. Each data processing device in the data center is therefore individually connected by electrically conducting cables and/or optical cables to the central gatekeeper. Since each data center typically has a relatively large number of individual data processing devices, the central gatekeeper must have a large number of electrical and optical input/output ports and a very high data switching capacity to accommodate all of the data traffic. Large port count gatekeepers are very expensive, on the order of hundreds of thousands of dollars each. To minimize expense, data centers are typically organized to use as few of the central gatekeepers as possible.
Minimizing the number of central gatekeepers in a data center requires that each of the data processing devices be connected to the central gatekeeper by individual electrical or optical cables. The electrical cables are typically high data rate twisted pair copper (TPC) conductors (e.g., TPC Category 15 cable) that are connected with conventional electrical connections to the data processing equipment at one end and to the central gatekeeper at the other end. The optical cables are typically clad optical fibers that are terminated at opposite ends by special techniques which transmit the optical signals through the termination connection with minimum loss of light energy. Optical fibers, which are capable of conducting signals at a high frequency or rate, must be specially and individually terminated to avoid light energy attenuation due to insertion losses and to assure the very high frequency signaling rate. The typical termination usually requires a trained technician with relatively extensive special equipment to accomplish the termination. Each termination costs in the order of a few hundred dollars.
The electrical and optical communication cables physically extend from the central gatekeeper to each of the individual data processing devices in the data center. Because each data center typically includes a large number of data processing devices, there are many hundreds of cables which must be routed physically from each data processing device through the space within the data center to the central gatekeeper. The communication cables are typically routed below a raised floor of the data center or hung by supports from the ceiling within the data center. In any event, there are a considerable number of cables in bundles which physically occupy the space within the data center.
The numerous data processing devices within the data center are usually physically supported in racks which extend from the floor to the ceiling, or within cabinets or enclosures which extend from the floor to near the ceiling. It is not unusual for ten to twenty data processing devices to be included in each rack, cabinet or enclosure. Each rack, cabinet or enclosure thereby forms a support structure for a group of data processing devices. The data processing devices of each support structure are connected to the central gatekeeper through a relatively large bundle of cables which are connected individually at their ends to the data processing devices of the support structure and to the central gatekeeper. The support structures are typically located at fixed positions within the data center. Fixing their position in the data center allows the communication cables to be extended and terminated at the fixed location to service the data processing equipment located in each support structure. A typical data center may have tens or hundreds of the fixed-position support structures. It is apparent that each data center therefore includes many hundreds or thousands of individual communication cables of relatively fixed lengths that are bundled together to accommodate each fixed-position support structure.
In addition to the physical restraints imposed by the bundles of specific length communication cables extending to each support structure, electrical power must be made available at the support structure to power the data processing equipment within that support structure. Because the support structure is fixed in position, the electrical power is typically delivered by electrical conductors confined in conduits to electrical power receptacles located at or close to each fixed support structure. The electrical power receptacles are therefore fixed in position within the data center.
The data processing devices of each support structure must also be cooled to prevent destruction or malfunction due to excessive heat. The traditional data center may have a raised floor which provides space below the support structures to distribute cooling air to the data processing devices of each support structure. Constructing a raised floor in a data center is very expensive because of the special structural supports required for the floor, and because of the airflow devices and ducts required to assure an adequate amount of cooling air to each support structure. As an alternative, ducts may be distributed in the ceiling by which to direct the cooling air on to each support structure and its data processing devices. In either event, the cooling capacity within the data center is fixed by the particular distribution of the cooling air ducts which are located to service the data processing devices of the fixed position support structures.
There often arises a need to redistribute the computational capacity of a data center to accommodate new and different projects or services. In such cases, it is desirable to physically move data processing from one location to another in the data center. This need sometimes arises because special projects require increased computational capacity, or because segments of the business organization grow and need additional computing devices, or because computational capacity needs to be redistributed if cooling limitations exist in the data center, i.e. hot spots. In most cases, it is desirable or required that the data processing devices assigned to a particular project or service be closely located in a physical sense. A close physical relationship will usually facilitate a cooperative and productive use of the computing facilities. In those cases where excess space is available in a support structure assigned to a particular project or service, additional data processing devices can be added to the support structure. However, this circumstance is unusual because the usual approach in data centers is to fully occupy each of the support structures before utilizing another support structure.
The need to move a relatively large number of data processing devices from one location to another in a data center has led to the use of mobile support structures. The mobile support structures are not fixed in position within the data center, but instead typically use casters or rollers to allow them to be rolled between different positions in the data center. The mobile support structures allow their data processing devices to be moved together as a group without removing them from the support structures.
However, mobile support structures do not address the problem of relocating and reconnecting the data processing devices caused by the relatively large bundles of electrical and optical conductors which individually connect the data processing devices to the central gatekeeper. The relatively expensive termination of the optical cables and the large number of electrical cables essentially restrict or tie the data processing equipment in position within the data center, except under the circumstance where new cables are extended and terminated at the new location of the data processing equipment. Extending and terminating the new cables is relatively expensive, which discourages movement of the data processing equipment within the data center. In addition to the cost, considerable downtime when the data processing equipment is not available for use also serves as a restriction on the ability to move the support enclosures and the data processing equipment. The requirements for electrical power may not be readily accommodated without extending new electrical power lines to those locations within the data center where the data processing devices may be relocated. A similar circumstance exists with respect to the cooling capacity. The thermal load created by an accumulation of data processing devices at a particular location in the data center may be so great as to limit the cooling capability in that particular location, and because the cooling capacity was originally anticipated to be more distributed. The thermal cooling capability also becomes more important as the size of the electronic equipment becomes more miniaturized, because the amount of heat generated in a given volume of space increases.